JPH01245023A - Novel aromatic amine resin and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title resin useful as a hardener for epoxy compound, etc., chelate resin, ion exchange resin adhesive, etc., by subjecting an amino-alpha- alkylbenzyl derivative to self-condensation in the presence of an acid catalyst using a specific aniline derivative as a terminator. CONSTITUTION:An amino-alpha-alkylbenzyl derivative (preferably o-, m- or p- amino-alpha-methylbenzyl alcohol) expressed by formula I (X is halogen, OH or a 1-4C alkoxy; R1 is 1-4C alkyl) is subjected to self-condensation in the presence of an acid catalyst (preferably hydrochloric acid) using an aniline derivative expressed by formula II (R2 is halogen, OH, 1-4C alkoxy or 1-5C alkyl; m is 0-3) as a terminator to provide the aimed resin expressed by formula III (n is 0-50).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel aromatic amine resin and a method for producing the same.

In addition to curing agents such as epoxy compounds, bismaleimide compounds, and isocyanate compounds, this aromatic amine resin can be used as an additive for various resins such as phenol resins and rubbers, or as a chelate resin, ion exchange resin, and deoxidizing agent by itself. It can be used in many ways, such as adhesives, insulating paints, and molding materials.

[Conventional technology]

Conventionally, as aromatic amine resins, condensates of aromatic amines and formalin have been known for a long time.For example, aniline resins represented by the formula are manufactured from aniline and formalin (Kei, Frey; , Himi Acta Vol. 18, 481 (I935)). This resin is widely used as a curing agent. However, when used as a curing agent in matrix resins for heat-resistant composite materials, heat-resistant adhesives, etc., it has the disadvantage that it cannot meet the advanced performance requirements of recent years.
- For example, materials for composite materials, adhesives, etc. are required to withstand instantaneous impacts such as stress concentration as external stress. For this reason, ideally, elastic deformation like rubber is attracting attention as an important element.

As a criterion for determining such elastic deformation, elongation of the matrix resin at break is particularly important. The greater the elongation of the matrix resin, the more it can compensate for the deficiencies of reinforcing agents such as glass fiber and carbon fiber required for composite materials. In other words, the strength of the composite material as a whole is improved.

Furthermore, in addition to heat resistance and dimensional stability, long-term storage stability is also important for these matrix resins, and they are also required to have little deterioration due to light and oxygen in the air. This oxidation resistance is mainly derived from the structure of the resin, and in addition to the above-mentioned requirements for mechanical strength, it has been difficult for aniline resins produced by formalin condensation to satisfy the above-mentioned requirements due to their structure.

[Problem to be solved by the invention]

The purpose of the present invention is to solve the various problems mentioned above, such as heat resistance, mechanical strength and dimensional stability when used as a curing agent,
The object of the present invention is to provide a novel aromatic amine resin with improved stability against light and oxygen in the air, and a method for producing the same.

[Means to solve the problem]

The present invention is based on l) formula (+) (wherein R1 represents a lower alkyl group having 4 or less carbon atoms,
R1 represents a halogen atom, a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms;
And R2 may be the same or different, and may form a ring. m represents an integer of 0 to 3, and n represents an integer of 0 to 50.

2) Amino- represented by formula (II) Bi1 (wherein, X represents a halogen atom, a hydroxyl group, or a lower alkoxy group having 4 or less carbon atoms, and R9 represents a lower alkyl group having 4 or less carbon atoms) When α-alkylbenzyl derivatives are self-condensed in the presence of an acid catalyst, the formula (III) (wherein,
R2 represents a halogen atom, a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms,
and Rt may be the same or different, and 0m which may form a ring represents an integer of 0 to 3). This is a method for producing a group amine resin.

The aromatic amine resin of the present invention exhibits excellent performance when used as a curing agent for bismaleimide resins and epoxy resins.

For example, when used as a curing agent for bismaleimide derived from methylene dianiline, the bending strength and flexural modulus of the cured resin are as follows. It is superior to resins, and its glass transition temperature, heat distortion temperature, and thermal decomposition onset temperature are almost the same.

In addition, the prepolymer has a low softening temperature (and a relatively long gelation time), which facilitates melt impregnation into glass fibers and the like.

Additionally, the prepolymer is soluble in low boiling solvents such as dioxane, methylene chloride, and the like.

This is because unlike kelimide, which is impregnated by dissolving it in a high boiling point aprotic polar solvent such as N-methylpyrrolidone, it can be impregnated with a low boiling point solvent, and volatile matter can be removed very easily. Are better.

On the other hand, even when used as a curing agent for epoxy resin derived from 2.2-bis(4-hydroxyphenyl)propane, the performance of the cured product is lower in bending strength, tensile strength, Excellent elongation, etc.

In addition, when trying to increase the molar ratio of formalin to increase the degree of condensation in order to improve mechanical strength, the aniline-formalin resin becomes a crosslinked structure, and the molecular weight becomes at most 60.
(Noda et al., Industrial Chemistry Journal Vol. 55,
484-487 (I952)), the aromatic amine resin of the present invention can be prepared by changing the molar ratio of the amino-α-alkylbenzyl derivative of formula (II) and the aromatic amine of formula (III). In formula (I), n can be arbitrarily selected from low molecular weight resins containing O as a main component to high molecular weight resins where n is up to about 50. As a result, various forms can be used depending on the application, ranging from liquid at room temperature to high softening point resin. For example, liquid or low softening point products are easier to work with such as melt compounding, impregnation, and coating. Excellent for adhesives,
Mainly used in fields such as paints, urethanes and additives to other resins. Those with a high softening point can be used in fields such as molding materials, ion exchange resins, and laminated resins.

It is clear from the results of infrared analysis and the like that the aromatic amine resin of the present invention consists mostly of secondary amines.

Such an aromatic amine resin can be obtained by the method described below.

First, X of the amino-α-alkylbenzyl derivative represented by formula (n) is a halogen atom such as a chlorine atom, a bromine atom, a fluorine atom, or an iodine atom, a hydroxyl group, or a lower alkoxy group having 4 or less carbon atoms, The alkyl group represented by R3 located at the α-position of the benzyl group is a lower alkyl group having 4 or less carbon atoms. In addition, the substitution position of the amino group is relative to the benzyl group.
They are the m-position, the m-position and the p-position, and a mixture thereof may also be used.

Such an amino-α-alkylhensyl derivative represented by formula (II) can be produced by nitration-reduction of the corresponding α-alkylbenzyl derivative. Moreover, when X is a hydroxyl group, it can also be produced by reduction of a nitroalkylophenone represented by the following formula (rV).

Amino-α-alkylbenzyl derivatives that can be produced by these methods include 0-amino-α-methylbenzyl chloride, m-amino-α-methylbenzyl chloride, and p-amino-α-methylbenzyl chloride.
-amino-α-methylbenzyl chloride, 0-amino-
-Methylbenzyl bromide, m-amino-α-methylbenzyl bromide, p-amino-α-methylbenzyl bromide, 0-amino-α-methylbenzyl iodo, p-amino-α-ethylbenzyl chloride, p-amino-α -isopropylbenzyl fluoride, 0-amino-α-methylbenzyl alcohol, m-amino-α-
Methylbenzyl alcohol, P-amino-α-methylbenzyl alcohol, O-amino-α-ethylbenzyl alcohol, m-amino-α-isopropylbenzyl alcohol, 0-amino-α-5ec・butylbenzyl alcohol, m-amino- α-n-butylbenzyl alcohol, 0-amino-α-methylbenzyl methyl ether, m-amino-α-methylbenzyl methyl ether,
p-amino-α-methylbenzyl methyl ether, p-
Amino-α-isopropylbenzyl methyl ether, 0
-amino-α-methylbenzyl isopropyl ether,
Examples include p-amino-α-methylbenzyl-n.propyl ether and p-amino-α-ethylbenzyl-n.butyl ether.

Among these, the most preferred amino-α-alkylbenzyl compounds of the present invention include 0-lm- and/or p-
-amino-α-methylbenzyl alcohol.

The aromatic amine resin represented by the formula (I) of the present invention is produced by self-condensing this amino-α-alkylbenzyl derivative in the presence of an acid catalyst. The aniline derivative represented is used as end-stopping agent.

The role of the aniline SA '4 body as a terminal stopper is the molecule of the aromatic amine resin of the present invention! It is important not only for controlling t1il but also for suppressing changes over time such as thickening of the product over time. In applications that do not require these roles, there is no problem in using only the amino-α-alkylbenzyl derivative after self-condensation.

In the method using this aniline derivative, amino-
The amount used per mole of α-alkylbenzyl derivative is:
It ranges from 0.02 to 20 mol, preferably from 0.1 to 10 mol. These may be charged in advance into the reactor at the same time as all the raw materials containing the amino-α-alkylbenzyl derivative (or may be added during the reaction).

6 of such aniline derivatives represented by formula (I[I)
is a halogen atom, a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms, and there are 0 to 3 of these, which may be the same or different from each other and form a ring. Specifically, aniline, 〇-
Toluidine, m-toluidine, p-toluidine, 0-ethylaniline, m-ethylaniline, P-ethylaniline, 0-isopropylaniline, m-isopropylaniline, P-isopropylaniline, 0-n.propylaniline, o-tert・Butylaniline, p-tert
・Butylaniline, 0-n・butylaniline, p-5
ec ・Butylaniline, 2.3-xylidine, 2.
4-xylidine, 2.6-xylidine, 3.4-xylidine, 3.5-xylidine, 2-methyl-3-ethylaniline, 2-methyl-4-isopropylaniline, 2.
6-dichloroaniline, 2-ethyl-5-jerL-butylaniline, 2,4-diisopropylaniline, 2,
4.6-) Limethylaniline, 4-chloroaniline,
4-bromoaniline, 4-fluoroaniline, 3-chloroaniline, 3-bromoaniline, 3.4-dichloroaniline, 3-chloro-〇-toluidine, 3-chloro-p
-Toluidine, 2,6-dimethyl-4-chloroaniline, 0-aminophenol, m-aminophenol, p-
Aminophenol, 2-amino-4-cresol, 4-
Amino-2・Lert-butylphenol, 2.6-dimethyl-4-aminophenol, 2.6-dichloro-4
-aminophenol, 2-amino-1,3-resorcin, 4-amino-1,3-resorcin, 2-aminohydroquinone, 2-methoxyaniline, 3-methoxyaniline, 4-methoxyaniline, 2-isopropoxyaniline, Examples include 2,4-dimethoxyaniline, 1-naphthylamine, 2-naphthylamine, and 1,1-dimethyl-4-aminoindan. Among these, preferred compounds are aniline, toluidine, xylidine, and aminophenols, and particularly preferred is aniline.

Acid catalysts include inorganic or organic acids, especially mineral acids, such as hydrochloric acid, phosphoric acid, sulfuric acid or nitric acid, Friedel-Kraf type catalysts such as zinc chloride, stannic chloride, aluminum chloride, ferric chloride; Alternatively, methanesulfonic acid or P
−) organic sulfonic acids such as luenesulfonic acid;
Super strong acids such as trifluoromethanesulfonic acid and Nafion H (trade name: manufactured by Dubon) may be used alone or in combination; industrially preferred is inexpensive hydrochloric acid. The amount of the catalyst used is in the range of 1 mol% to 100 mol%, preferably 3 mol%, when the total amount of the amino-α-alkylbenzyl derivative and aniline derivative as raw materials is 1 mol.
~50 mol%. In addition, when X of the amino-α-alkylbenzyl compound represented by formula (II) as a raw material is a halogen atom, there is no need to use a catalyst. The reaction temperature ranges from 20°C to 150°C, preferably from 40 to 1
A temperature of 30°C is desirable.

Reaction time is 1 to 10 hours.

In the method of the present invention, an inert solvent may be used for the reaction, or the reaction may be carried out without a solvent. 8 As the solvent, aromatic hydrocarbons such as benzene, toluene, monochlorobenzene, and nitrobenzene, and ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether are often used. , neutralized with a dilute alkaline aqueous solution such as potassium hydroxide aqueous solution or aqueous ammonia, and then separated into liquids.

If unreacted aromatic amine compounds remain, they are distilled off under vacuum or by water vapor distillation.

The aromatic amine resin of the present invention is obtained in the manner described above.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 330.4 m-nitroacetophenone in a 31 airtight container
(2 mol), 13.2 g of 5% Pd/C catalyst and 2000 ml of methanol, and hydrogen was introduced with vigorous stirring. When the reaction was continued for 12 hours while maintaining the reaction temperature at 50 to 55°C, 179N of hydrogen was absorbed and no further absorption was observed, so the reaction was terminated.

Next, this reaction system was purged with nitrogen, and then filtered to remove the catalyst. After concentrating the iIl solution, vacuum distillation was performed to obtain m-amino-α
-255.2 g of methylbenzyl alcohol was obtained. Yield 93%.

Boiling point 135~136° (/3 mmHg, melting point 64~
65°C Elemental analysis value CII N Calculated value (χ) ? 0.05 8.08 10.21
Measured value (χ) 70.52 8.10 10.14
Next, 68.6 g (0.5 mol) of this m-amino-α-methylbenzyl alcohol and 46.5 g (0.5 mol) of aniline were added.
, 5 mol) was charged into a reactor, 21 g (0.2 mol) of a 35% aqueous hydrochloric acid solution was added to the catalyst, and the temperature was raised while nitrogen gas was introduced.

Without removing the distilled water from the system, raise the temperature to 120°C,
After completion of the 0 reaction, which was maintained at the same temperature for 3 hours, 50 ml of water was added, further 50 ml of toluene was added, and the mixture was neutralized with 30 g of a 30% aqueous solution of caustic soda. After stirring at 70-80°C for 1 hour, the mixture was allowed to stand and was separated into 2N. After separating and removing the lower aqueous layer, azeotropic dehydration was performed under refluxing toluene, and this was filtered to remove trace amounts of inorganic salts. Vacuum 1
41i1! After completely removing toluene and some unreacted aniline, a light yellow transparent formula (where R1 is a methyl group and R
Aromatic amine resin 6 corresponding to the case where 2 is absent (m=o)
8g was obtained.

The results of compositional analysis by high performance liquid chromatography show that in formula (I), n=o is 20.5%, n-1 is 33.2, n-2 is 28.6, n=〉3 is 17.7, and the average The molecular weight is 390, and the amine equivalent N (according to the perchloric acid-glacial acetic acid method) of this resin is equivalent weight/(I00g) = 0.87, JIS-
-2548 had a softening point of 46°C.

The results of infrared analysis are shown in Figure 1.

Examples 2 to 4 The same procedure as in Example 1 was carried out except that the m-amino-α-methylhensyl alcohol obtained in Example 1 was used and the type and amount of the aniline derivative and the type and amount of the catalyst were changed. , various aromatic amine resins were obtained.

The results are shown in Table 1.

Example 5 5.4 g (0.05 mol) of 0-toluidine was added as an aniline derivative to 34.3 g (0.25 mol) of m-amino-α-methylbenzyl alcohol obtained in Example 1.
Add 0.57 g (0,003 g) of p-toluenesulfonic acid to the catalyst.
mol) and toluene 20-1 as a solvent, the reaction was carried out under reflux of toluene for 8 hours. During the reaction, the water generated in the reaction was removed from the yarn using a water separator. After the reaction, it was neutralized with 10 ml of 1% dilute ammonia water, and then 50 ml of toluene was added.
When 1 was added and left to stand, it was separated into 2N.

The lower aqueous layer was separated and removed, and a water washing and separation operation was performed once. Next, the solvent toluene was distilled off under reduced pressure and discharged into a porcelain vessel to obtain a pale yellow resin.

Yield 135g.

Softening point 108°C The average molecular weight was 3200.

Example 6 A reactor was charged with 122.2 g (1 mole) of 1-phenylethanol and 3001 L2-dichloroethane, and -5
Cooled to °C. Next, add 80g of 95% nitric acid and 36g of concentrated sulfuric acid.
0 g of mixed acid was added dropwise over 5 hours at a temperature of 0 to -5°C. After aging at the same temperature for 1 hour, 500 g of ice water
g, and the lower waste acid layer was separated and removed. Next, 500 g of water was added, and the organic layer was concentrated by washing with water to obtain 168 g of a pale yellow oil. As a result of gas chromatography and 1H-NMR analysis, it was found that 4-
The composition contained 94.5% nitro-α-methylbenzyl alcohol.

'H-NMR (CDCb, TMS) 61.7 (3H,d CH(OR)Me)6
．． 1 (I)1. Q CH(011)Me)7
．． 65 (2■, d 2,6H, Jg-s, b-s
□ 8.0Hz) 8.35 (2H, d 3.5H+
J3-! +S-4" 8.0H2) Next, this composition was reduced with hydrogen in an autoclave using 500ml of methanol and 5g of 5% Pd/C catalyst. The reaction temperature was 25-35°C, hydrogen pressure 5 ~3 at 10Kg/d
After 0 hours of reaction, the catalyst was removed by filtration, and methanol as a solvent was distilled off. When left to stand, it crystallized, so a small amount of methanol was added and filtered to obtain 97.5 g of 4-amino-α-methylbenzyl alcohol (JK yield: 71%).

The melting point was 91-93°C, and the results of elemental analysis were as follows.

Elemental analysis value (CsLJO) CII N Calculated value (χ) 70.0 B, 1 10.2 Measured value (χ) 69.8 B, 3 10.0 68.6 g of this 4-amino-α-methylbenzyl alcohol
(0.5 mol) and 186.2 g (2 mol) of aniline were charged into the reactor, and 18.2 g (0.5 mol) of dry hydrogen chloride gas was charged to the catalyst.
0.5 mol) was introduced to carry out the reaction.

The reaction temperature was 50 to 80°C, and the reaction time was 5 hours. After the reaction was completed, 85 g of a 15% aqueous sodium hydroxide solution was added to the slightly viscous solution, and when the solution was thoroughly stirred and allowed to stand, it separated into two layers. Remove the lower aqueous layer and add 20% saline solution 100%
g was added and the mixture was washed and separated. This was condensed under reduced pressure to recover unreacted aniline to obtain a pale yellow oily aromatic amine resin.

Yield was 72g, average molecular weight 1260.

Example 7 20.1 g of 4-amino-α-methylbenzyl bromide
(0,1 mol) and 60°6 g of 2,4-xylidine (0,
5 mol) was charged into the reactor, and the temperature was raised to 5 mol).
The post-treatment after the 0-reaction, in which the reaction was completed by keeping it at 0 to 70°C for 3 hours, was carried out in the same manner as in Example 6 to obtain 20.5 g of a pale yellow candy-like aromatic amine resin.

The average molecule It was 270.

Example 8 4-amino-α-methylbenzyl methyl ether 15.
1 g (0.1 mol) and 107.2 g (I
, 0 mol) and 152 g of 35% aqueous hydrochloric acid as a catalyst were charged into a reactor and reacted for 7 hours under reflux of water. Post-treatment after the reaction was carried out in the same manner as in Example 6, and a pale yellow oily aromatic 19 g of group amine resin was obtained.

The average molecular weight was 245.

Example 9 m-amino-α-n-butylbenzyl alcohol 20.
A condensation reaction was carried out in the same manner as in Example 1 using 1 g (0.1 mol) of aniline, 18.6 g (0.2 mol) of aniline, and 10.4 g of a 35% aqueous hydrochloric acid solution to obtain an aromatic amine resin in the form of a pale yellow resin. 22.5g was obtained.

The softening point was 42°C.

Example 1O In a reactor, 120 g (1 mole) of acetophenone and 1.2-
300 ml of dichloroethane was charged and cooled to 0°C.

Next, a mixed acid consisting of 80 g of 95% nitric acid and 360 g of concentrated sulfuric acid was added dropwise at a temperature of 0 to 10° C. over 5 hours to perform a nitration reaction. Post-treatment was carried out in the same manner as in Example 6 to obtain 162 g of crude crystals of nitroacetophenone.

Yield 98%.

The analysis results by gas chromatography are all 8.2
% Zen 89.4% P 1.1% Others 1.3%.

At the same time, this crude ditroacetophuninone was mixed with 5% Pd/C.
Reduction was carried out under the same conditions as in Example 1 using 9 g of catalyst and 1000+ wl of methanol to obtain 128 g of crude amino-α-methylbenzyl alcohol, total yield 93.3%, gas chromatography analysis of nitro form. The values were almost the same.

For this crude amino-α-methylbenzyl alcohol,
Using 259 g (2.78 mol) of aniline and 97 g (0.93 mol) of 35% aqueous hydrochloric acid solution, the same procedure as in Example 1 was carried out to obtain 158 g of a pale yellow candy-like aromatic amine resin.

The average molecular weight was 275.

Usage Example 1 40 parts by weight of the aromatic amine resin obtained in Example 1 and 100 parts by weight of Bismaleimide-5 (manufactured by Daiwa Kasei Kogyo) were mixed and melted by heating at 180'C for 10 minutes to form a prepolymer. Created.

The solubility of this prepolymer in various solvents was measured. The results are shown in Table 2 as Experimental Example 1. Furthermore, the appearance, softening temperature, gelling time, and bulk specific gravity of this prepolymer are shown in Table 3 as Experimental Example 1. For comparison, the results of a similar test using commercially available Kelimide-1050 (trade name: Molding Grade, manufactured by Nippon Polyimide ■) are shown in Tables 2 and 3 as Comparative Experimental Example 1.

Next, this prepolymer and Kelimide-1050 were each compression molded at a temperature of 200°C under a pressure of 40 g/cd for 1 hour, and then post-cured at 250°C for 4 hours to form a cured product. A test piece was prepared.

The mechanical strength and thermal properties of this test piece were measured. The results are shown in Table 3 as Experimental Example 1 and Comparative Experimental Example 1, respectively.

Use Example 2 The aromatic amine resin obtained in Example 6.9 was used as a curing agent for Epicote 828 (Shell chemical type). For comparison, an aniline resin produced from aniline-formalin having an average molecular weight of 300 was similarly used.

These were blended under the conditions shown in Table 4, the mixture was cast, and the mechanical properties of the cured resin after processing were measured. The results are shown in Table 4.

[Effects of the Invention] As explained above, when the aromatic amine resin of the present invention is used as a curing agent, the resulting cured resin has excellent heat resistance and mechanical strength. Furthermore, when used as a curing agent for bismaleimide, since the prepolymer is soluble in a low boiling point solvent, workability in blending, impregnation, etc. is good.

Such an aromatic amine resin of the present invention can be produced from inexpensive raw materials through simple operations, and can be obtained in a non-polluting manner without producing by-products.

[Brief explanation of the drawing]

Figure 1 shows the IR of the aromatic amine resin obtained in Example 1.
It is a figure showing an analysis result.

Claims (1)

[Claims] 1) Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a lower alkyl group having 4 or less carbon atoms, and R_2 represents a halogen atom, a hydroxyl group, a carbon Represents a lower alkoxy group with a number of 4 or less or a lower alkyl group with a carbon number of 5 or less, and R_2 may be the same or different and may form a ring. m represents an integer of 0 to 3, n is 0 to 5
Indicates an integer of 0. ) Aromatic amine resin represented by 2) Formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, X represents a halogen atom, a hydroxyl group, or a lower alkoxy group having 4 or less carbon atoms, and R_1 is a lower alkyl group having 4 or less carbon atoms. When self-condensing an amino-α-alkylbenzyl derivative represented by (representing a group) in the presence of an acid catalyst, there are formula (III) ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (III) (in the formula, R_2 represents a halogen atom, a hydroxyl group, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms, and R_2 may be the same or different and may form a ring. m is 0 A method for producing an aromatic amine resin, characterized in that an aniline derivative represented by